Crescendo REVOLUTION 7A4 4 Channel Amplifier

The Crescendo Revolution 7A4 produces 150 watts per channel at 4 ohms, 240 watts per channel at 2 ohms, and 480 watts per channel bridged at 4 ohms, all rated at 14.4 volts. It is the flagship 4-channel in the Revolution series, a Class AB High Bias design with a 2-ohm minimum speaker load.

The 7A4 combines the most power in the Revolution 4-channel line with the most refined signal path. It doubles the per-channel output of the Revolution 5A4 (150 watts versus 75 watts at 4 ohms), adds an audio-grade signal path built on Burr Brown chips and Elna capacitors, a dual symmetrical power supply, individually balanced channels, and a preamplifier bypass option, and measures 0.0035% THD with response from 5 Hz to 100 kHz at a strict -0.5 dB window.

Burr Brown chips handle the preamp stage and Elna audio-grade capacitors sit in the signal path, both chosen for extremely low noise and distortion. These are components more commonly found in high-end home audio equipment, and they are a large part of why the 7A4 measures 0.0035% THD and 110 dBA signal-to-noise, keeping the amplifier sonically invisible between the processor and the speakers.

The preamplifier bypass routes the signal past the amplifier's input gain stage entirely, shortening the signal path for the purest possible amplification. It is designed for use with processors that output a strong, properly leveled signal, since the amplifier's input sensitivity range of 900 mV to 5 V is bypassed along with the gain stage. For most installations the standard gain path is appropriate; the bypass is the purist option.

No. Like every Revolution series amplifier, the 7A4 is a pure power amplifier with no onboard filter, designed for systems where a DSP handles crossover points, time alignment, and EQ. Pairing it with a quality processor such as a Goldhorn DSP creates a reference-grade signal chain: digital processing followed by pure Class AB High Bias amplification.

Yes, within its ratings. Bridged, the 7A4 delivers 480 watts per channel at 4 ohms, which suits a sound-quality-oriented subwoofer or a pair of high-output midbass drivers. Its minimum load is 2 ohms in stereo and 4 ohms bridged, so plan subwoofer wiring accordingly. For dedicated high-power subwoofer duty at low impedances, the Revolution 5A1 monoblock with its constant 450 watts down to 1 ohm is the purpose-built choice.

Most amplifiers quote frequency response at -3 dB, the point where output has already fallen noticeably. The 7A4's 5 Hz to 100 kHz response is specified at -0.5 dB, a far stricter window, meaning the amplifier is essentially flat across a bandwidth that comfortably exceeds high-resolution audio formats. In practice, nothing in the audible range is rolled off, shaped, or colored.

The Revolution 7A4 measures 360 by 215 by 54 millimeters (14.2 by 8.5 by 2.1 inches) and weighs 4.5 kilograms (9.9 pounds). Its low 2.1-inch profile suits clean rack installations alongside other Revolution amplifiers. Working voltage is 10 to 16 volts, onboard fusing is 2 x 50 amps, and protection covers thermal and short circuit conditions. Fuse the power run at the battery as with any amplifier of this output.